1. Field of the Invention
The present invention relates to an electronic apparatus and a hard disk drive housing apparatus, and particularly to an electronic apparatus and a hard disk drive housing apparatus in which radiated heat and a noise from an electronic apparatus and a hard disk drive housing apparatus can be absorbed so that the electronic apparatus and the hard disk drive housing apparatus can be prevented from being affected by shock from the outside.
2. Description of the Related Art
A known case main body for accommodating therein a drive unit rotating at high speed within a hard disk drive (HDD) has had an airtight property in order to prevent hearing a noise generated when the drive unit is rotated and vibrated. Such an airtight case main body encounters problems in that, because it has no holes and thus no air convection, it accumulates heat and cannot sufficiently radiate heat. To solve the above-mentioned problems, cited patent reference 1 has disclosed an HDD housing structure in which two problems of heat radiation and absorption of vibration can be solved effectively while the airtight property can be maintained.
FIG. 1 of the accompanying drawings is a schematic perspective view showing a HDD housing structure disclosed in the cited patent reference 1.
As shown in FIG. 1, the above-described cited patent reference 1 discloses a housing structure for housing a HDD 7 in which a hard disk drive unit and the like are housed within a flat case 1 of which outward appearance is substantially a rectangular solid and in which noise absorption members 4a, 4b, 4c and 4d are provided within the case 1. As shown in FIG. 1, the case 1 is composed of a case lid 2 and a box-like case main body 3 with the case 2 mounted to an open bottom portion thereof. Noise absorption members 4a, 4b, 4c and 4d, each of which has a predetermined thickness, are disposed along the inner wall portion around the case main body 3. A heat radiation plate 5 is located on the inside of the top portion 3a of the case main body 3 and a drive unit is located between supporting members 6L and 6R erected from the heat radiation plate 5 to the inside of the case main body 3. In order to enable the heat radiation plate 5, the supporting members 6L, 6R and the case lid 2 to form a heat radiation structure which contacts with the drive unit to radiate heat from the drive unit, the case lid 2, the case main body 3, the heat radiation plate 5 and the supporting members 6L, 6R are made of aluminum or aluminum alloy.
According to this arrangement, the noise absorption members 4a, 4b, 4c and 4d can absorb a vibration noise and they can also decrease leakage of a noise to the outside. In addition, the case lid 2, the case main body 3, the heat radiation plate 5 and the supporting members 6L, 6R are made of material having excellent heat transmission property and hence heat radiation effect of the drive unit can be exhibited.
As shown in FIG. 1, the noise absorption members 4a, 4b, 4c and 4d are made of a sponge-like soft synthetic resin or a natural rubber and a part of the noise absorption members 4a, 4b, 4c and 4d can kept its position in the state in which it is held between the inner wall surface of the case main body 3 and the supporting members 6L, 6R. Also, the heat radiation plate 5 is attached to the inner surface of the case lid 2 through a member with high heat transmission property and cushion property, for example, a square plate member 8 made of an adhesive synthetic resin commercially available under the trade name of “SORBOTHANE” and this heat radiation plate 5 is brought in contact with the drive unit of the HDD 7. A second heat radiation plate 5a is provided between the case lid 2 and the heat radiation plate 5 and it is brought in contact with the case lid 2 through the second square member 8a and the noise absorption member 4d. Accordingly, heat is transmitted from the heat radiation plate 5a to the case lid 2 by the second square plate member 8a with the high heat transmission property and the cushion property.
Further, a cited patent reference 2 has disclosed a structure to completely house a hard disk (HD) into a box made of a noise absorption material 4 as an attachment structure in which a noise generated from the HDD 7 can be decreased and in which heat radiation efficiency can be improved.
FIG. 2 is a cross-sectional side view showing the HDD 7 disclosed as an example of the related art of the cited patent reference 2. This related-art example has a silent disk drive structure that has been described in the specification of U.S. Pat. No. 5,510,954. The related-art example is composed of the noise absorption member 4 provided in the periphery of the HDD 7, a noise insulation case 15 provided in a heat sink 9 and a heat transmission path 10.
Specifically, as shown in FIG. 2, a disk drive 11 of the HDD 7 is enclosed by a heat transmission and vibration absorption member 12 and a metal case 13 of the HDD 7. The noise absorption member 4 is provided between the metal case 13 and the noise insulation case 15 and the metal case 13 and the heat sink 9 is connected by the heat transmission path 10.
According to the arrangement of the HDD 7 described in the above-mentioned cited patent reference 1, the noise absorption members 4a to 4d and the two heat radiation plates 3 and 3a are housed within the case main body 3 and the case lid 2 comprising the case 1 and there arises a problem, in which the case 1 of the HDD 7 becomes large in size.
Also, according to the arrangement of the HDD 7 described in the above-mentioned cited patent reference 2, the following problems arise in addition to the problem encountered with the above-mentioned cited patent reference 1.
Since the HDD 7 containing the HD (disk drive 11) generates a large amount of heat and it should be kept under a certain circumstance temperature in order to maintain function reliability, when the HDD 7 is completely housed within the box of the noise insulation case 15 covered with the noise absorption member 4, heat radiation effect becomes a serious problem depending upon the surrounding air circumstance conditions. Although heat is radiated by the heat sink 9 located outside the noise insulation case 15 through the heat transmission path 10 in the cited patent reference 2, in the case of the HDD which generates a large amount of heat, there is a limit to generate heat by using only the heat sink 9 and hence it becomes difficult to keep the HD within the HDD 7 and the head under a constant circumstance temperature.
Also, in order to increase heat radiation efficiency, the heat sink 9 should become large in size and hence the space is increased, which makes the whole of the HDD 7 become larger in size. When external force such as shock is applied to such heat sink 9 from the outside, the disk drive of the HDD 7 is directly vibrated and problems arise, in which the pickup head and the like will be broken.
Further, as a condition under which the HDD 7 is mounted on the electronic apparatus, there is prescribed that the HDD 7 should be mounted with a constant distance from other components to be mounted. The reason for this is that an atmospheric pressure within the metal case 13 of the HDD 7 should be kept constant and breathing holes should be closed so that stress may not be applied to the HD. In the arrangement shown in FIG. 2, since the heat transmission path 10 directly comes in contact with the HDD 7, a problem arises, in which function reliability of the disk drive 11 will be affected.
[Cited patent reference 1]: Official gazette of Japanese laid-open patent application No. 2002-74929
[Cited patent reference 2]: Official gazette of Japanese laid-open patent application No. 11-66832